Volume-rendered Images Research Articles

Three-Dimensional Printing Facilitates Creation of a Biliary Endoscopy Phantom for Interventional Radiology-Operated Endoscopy Training

To create a three-dimensional endoscopic model of the biliary tract from magnetic-resonance cholangiopancreatography imaging and to evaluate its effectiveness as a tool for training in endoscopic biliary interventions. A magnetic-resonance cholangiopancreatography study was performed on a patient with biliary obstruction secondary to a distal bile duct cholangiocarcinoma. Using Vitrea, a three-dimensional volume-rendered image was created, and exported as a standard tessellated language file. The standard tessellated language model was then edited with MeshMixer. Three cylindrical entry ports were created. The ports were aligned and overlapped with the dominant ducts in three separate areas of the model and fused to the model. A 0.2 cm shell was created around the model and the model was hollowed. The ends of the ports were cut off, allowing access to the hollowed-out model. The model was printed at 125% scale to allow easy access with a 9.5-French (≤3.23 mm) endoscope. The model was printed using a Stratasys Dimension Elite Plus printer. After printing, the model was post-processed to remove support materials. A 10-question survey was administered to all trainees before and after use of the printed phantom to practice endoscopy skills. 11 trainees participated in the three-dimensional endoscopy simulation with most of the trainees (73%) having no prior formal endoscopy training. Using a 10-point Likert scale, the mean comfort-level of the trainees to use endoscopy alone for cholecystostomy, percutaneous biliary drainage, percutaneous nephrostomy, and percutaneous gastrostomy increased by 38.9%, 32.8%, 32.8%, and 34.3%, respectively, following the training experience. The use of a three-dimensionally printed endoscopic model as a simulation tool has the potential to improve trainee comfort using endoscopy during interventional radiology procedures.

Part I – Adult skeletal age estimation using CT scans of cadavers: Revision of the fourth rib methods

Abstract Objective CT scans have become a standard part of autopsy procedures in large medical-legal facilities, and forensic anthropologists are increasingly asked to contribute their knowledge of skeletal anatomy to volume-rendered images (VRIs) generated from CT scans. However, it is not clear if the age estimation methods created using skeletal remains can be reliably applied to VRIs. This study, along with the other two in this series, examines the applicability of three commonly used sites for adult skeletal age estimation on VRIs generated from CT scans of cadavers. Part I focuses on the fourth rib. Materials and methods CT scans of 420 cadavers from the Victorian Institute of Forensic Medicine were selected (age range 20–79 years). Siemens syngo.via software was used to view the DICOM images and create the VRIs. The Iscan et al. and Hartnett fourth rib methods of age estimation were used to create a revised method for VRIs. Results and conclusion Several features described by both Iscan et al. and Hartnett could be observed on the VRIs; however, features such as porosity inside the sternal rib and bone weight could not be assessed. A revised fourth rib method for use on VRIs was created. Significantly more individuals were placed in the correct age phase using the revised method compared to the Iscan et al. and Hartnett methods, and overall the revised method had significantly improved inaccuracy and bias scores. The revised method is reliable and should be tested on other populations using different software.

Part II-adult skeletal age estimation using CT scans of cadavers: Revision of the pubic symphysis methods

Abstract Objective When present, the most commonly used element to estimate adult skeletal age at death is the pubic symphysis. In the second manuscript of this series, the Suchey–Brooks and Hartnett pubic symphysis methods are assessed to for their applicability to volume-rendered images (VRIs) generated from CT scans of cadavers to assess their applicability to VRIs. Materials and Methods CT scans of 420 cadavers from the Victorian Institute of Forensic Medicine were selected (age range 20 to 79 years). Siemens syngo.via software was used to view the DICOM images and create the VRIs. The Suchey–Brooks and Hartnett pubic symphysis methods were used to create a revised method to estimate age for VRIs. Results and Conclusion Several features described by Suchey–Brooks and Hartnett could be observed on the VRIs, including billows on the symphysis face in younger individuals, the ventral rampart, and the dorsal margin. However, distinguishing features such porosity and bone weight for the older phases could not always be assessed. A revised pubic symphysis method for use on VRIs was created using both morphological features and bone quality to assess age. The revised method is strongly correlated with age, and over 70% of the sample was placed in the correct age phase. The Suchey–Brooks method was more accurate for individuals under 40 years of age while the revised method was more accurate for individuals over 40 years of age, similar to the findings from other studies. This revised method should be tested on other populations using different CT settings and software.

Part III – Adult skeletal age estimation using CT scans of cadavers: Revision of the auricular surface methods

Abstract Objective The auricular surface of the ilium is often found preserved in both archaeological and forensic contexts. In the final manuscript of this three-part series, the features used by biological and forensic anthropologists to estimate adult skeletal age from the auricular surface are tested on volume-rendered images (VRIs) generated from CT scans of cadavers. Materials and methods CT scans of 420 cadavers from the Victorian Institute of Forensic Medicine were selected (age range 20–79 years). Siemens syngo.via software was used to view the DICOM images and create the VRIs. The Lovejoy et al. auricular surface method of age estimation was assessed for use on VRIs and a new method for VRIs was created. Results and conclusion Most of the features described by Lovejoy et al. could not be observed on the VRIs, and as previously established by Villa et al. (2013) [13], the Buckberry and Chamberlain method cannot be used on VRIs. Features such as transverse organization, surface texture, and microporosity are not visible on VRIs; however, features of the auricular surface and retroauricular area were seen to progress in a manner similar to that described by Lovejoy and colleagues, and a revised auricular surface method for use on VRIs was developed. The revised method is strongly correlated with age, and over 70% of the sample was placed within one standard deviation of the mean of the correct phase. This revised method should be tested on more populations using different CT settings and software.

Acute Limited Intimal Tears of the Thoracic Aorta

BackgroundLimited intimal tears (LITs) of the aorta (Class 3 dissection variant) are the least common form of aortic pathology in patients presenting with acute aortic syndrome (AAS). LITs are difficult to detect on imaging and may be underappreciated. ObjectivesThis study sought to describe the frequency, pathology, treatment, and outcome of LITs compared with other AAS, and to demonstrate that LITs can be detected pre-operatively by contemporary imaging. MethodsThe authors retrospectively reviewed 497 patients admitted for 513 AAS events at a single academic aortic center between 2003 and 2012. AAS were classified into classic dissection (AD), intramural hematoma, LIT, penetrating atherosclerotic ulcer, and rupturing thoracic aortic aneurysm. The prevalence, pertinent risk factors, and detailed imaging findings with surgical and pathological correlation of LITs are described. Management, early outcomes, and late mortality are reported. ResultsAmong 497 patients with AAS, the authors identified 24 LITs (4.8% of AAS) in 16 men and 8 women (17 type A, 7 type B). Patients with LITs were older than those with AD, and type A LITs had similarly dilated ascending aortas as type A AD. Three patients presented with rupture. Eleven patients underwent urgent surgical aortic replacement, and 2 patients underwent endovascular repair. Medial degeneration was present in all surgical specimens. In-hospital mortality was 4% (1 of 24), and in total, 5 patients with LIT died subsequently at 1.5 years (interquartile range [IQR]: 0.3 to 2.5 years). Computed tomography imaging detected all but 1 LIT, best visualized on volume-rendered images. ConclusionsLITs are rare acute aortic lesions within the dissection spectrum, with similar presentation, complications, and outcomes compared with AD and intramural hematoma. Awareness of this lesion allows pre-operative diagnosis using high-quality computed tomography angiography.

Progressive Reduction in Gray Matter in Patients with Schizophrenia Assessed with MR Imaging by Using Causal Network Analysis.

HomeRadiologyVol. 287, No. 2 PreviousNext CommunicationsFree AccessErratumProgressive Reduction in Gray Matter in Patients with Schizophrenia Assessed with MR Imaging by Using Causal Network AnalysisYuchao Jiang, Cheng Luo, Xin Li, Mingjun Duan, Hui He, Xi Chen, Hang Yang, Jinnan Gong, Xin Chang, Marie Woelfer, Bharat B. Biswal, Dezhong YaoYuchao Jiang, Cheng Luo, Xin Li, Mingjun Duan, Hui He, Xi Chen, Hang Yang, Jinnan Gong, Xin Chang, Marie Woelfer, Bharat B. Biswal, Dezhong YaoYuchao JiangCheng LuoXin LiMingjun DuanHui HeXi ChenHang YangJinnan GongXin ChangMarie WoelferBharat B. BiswalDezhong YaoPublished Online:Apr 18 2018https://doi.org/10.1148/radiol.2018184005MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Originally published online:https://doi.org/10.1148/radiol.2017171832Erratum in:Radiology 2018;287(2):729 DOI:10.1148/radiol.2018184005Figure 2 legend should read as follows:MR images show stage-specific gray matter volume reductions in patients with schizophrenia (SZ) relative to the healthy controls. Reduced gray matter volume images were overlaid on a sagittal template, with coordinate planes in white. Color bar represents t values from two-sample t test. A, Subjects with SZ were categorized into three subgroups according to SZ duration (stage AI, 0–10 years; stage AII, 11–20 years; stage AIII, > 20 years). B, All patients were categorized into six subgroups (stage BI, 0–5 years; BII, 5–10 years; BIII, 10–15 years; BIV, 15–20 years; BV, 20–25 years; BVI, > 25 years).Article HistoryPublished online: Apr 18 2018Published in print: May 2018 FiguresReferencesRelatedDetailsCited ByEvaluation of gray matter reduction in patients with typhoon-related posttraumatic stress disorder using causal network analysis of structural MRIHui JuanChen, RongfengQi, JunKe, JieQiu, QiangXu, YuanZhong, Guang MingLu, FengChen2022 | Psychological Medicine, Vol. 52, No. 8Structural Covariance of the Ipsilesional Primary Motor Cortex in Subcortical Stroke Patients with Motor DeficitsXinyuanChen, MengchengLi, NapingChen, HuiminLai, ZiqiangHuang, YuqingTu, QunlinChen, JianpingHu, SergioBagnato2022 | Neural Plasticity, Vol. 2022Progressive Brain Structural Impairment Assessed via Network and Causal Analysis in Patients With Hepatitis B Virus-Related CirrhosisShiweiLin, ZhengGuo, ShengliChen, XiaoshanLin, MinYe, YingweiQiu2022 | Frontiers in Neurology, Vol. 13Neurodegenerative model of schizophrenia: Growing evidence to support a revisitWilliam S.Stone, Michael R.Phillips, Lawrence H.Yang, Lawrence S.Kegeles, Ezra S.Susser, Jeffrey A.Lieberman2022 | Schizophrenia Research, Vol. 243Multimodal magnetic resonance image and electroencephalogram constrained fusion algorithm using deep learningXiaofengLi, HeyanHuang2021 | Soft ComputingAbnormality of subcortical volume and resting functional connectivity in adolescents with early-onset and prodromal schizophreniaDanWen, JunjieWang, GuanqunYao, ShaLiu, XinrongLi, JingLi, HongLi, YongXu2021 | Journal of Psychiatric Research, Vol. 140BCCT: A GUI Toolkit for Brain Structural Covariance Connectivity Analysis on MATLABQiangXu, QiruiZhang, GaopingLiu, Xi-jianDai, XinyuXie, JingruHao, QianqianYu, RuotingLiu, ZixuanZhang, YuluYe, RongfengQi, Long JiangZhang, ZhiqiangZhang, GuangmingLu2021 | Frontiers in Human Neuroscience, Vol. 15Durational effect of particulate matter air pollution wave on hospital admissions for schizophreniaLijunBai, JingYang, YanwuZhang, DeshengZhao, HongSu2020 | Environmental Research, Vol. 187Neural primacy of the dorsolateral prefrontal cortex in patients with obsessive-compulsive disorderHailongLi, XinyuHu, YingxueGao, LingxiaoCao, LianqingZhang, XuanBu, LuLu, YanlinWang, ShiTang, BinLi, YanchunYang, Bharat B.Biswal, QiyongGong, XiaoqiHuang2020 | NeuroImage: Clinical, Vol. 28Disrupted structural covariance network in first episode schizophrenia patients: Evidence from a large sample MRI-based morphometric studyXiaoZhang, WenmingLiu, FanGuo, ChenLi, XingruiWang, HuaningWang, HongYin, YuanqiangZhu2020 | Schizophrenia Research, Vol. 224Compression of Cerebellar Functional Gradients in SchizophreniaDeboDong, ChengLuo, XavierGuell, YulinWang, HuiHe, MingjunDuan, Simon BEickhoff, DezhongYao2020 | Schizophrenia Bulletin, Vol. 46, No. 5The characterization of psychotic symptoms in succinic semialdehyde dehydrogenase deficiency: a reviewMark A.Colijn2020 | Psychiatric Genetics, Vol. 30, No. 6Gray matter atrophy patterns within the cerebellum-neostriatum-cortical network in SCA3JingGuo, HuiChen, Bharat B.Biswal, XiaonanGuo, HuangbinZhang, LimengDai, YuhanZhang, LiangLi, YunshuangFan, ShaoqiangHan, JuanLiu, LiuFeng, QiannanWang, JianWang, ChenLiu, HuafuChen2020 | Neurology, Vol. 95, No. 22Hippocampus-driving progressive structural alterations in medication-naïve major depressive disorderYutingLi, ChunWang, ChangjunTeng, KailiJiao, XiuSong, YarongTan, ChaoyongXiao, NingZhang, YuanZhong2019 | Journal of Affective Disorders, Vol. 256Increased Temporal Dynamics of Intrinsic Brain Activity in Sensory and Perceptual Network of SchizophreniaYouxueZhang, GangGuo, YuanTian2019 | Frontiers in Psychiatry, Vol. 10Accompanying This ArticleProgressive Reduction in Gray Matter in Patients with Schizophrenia Assessed with MR Imaging by Using Causal Network AnalysisJan 19 2018RadiologyRecommended 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Aortic Root Sign

Appearance: The aortic root sign describes an anomalous circumflex coronary artery (ACCA) that emerges from the contralateral coronary sinus, and travels underneath the aorta to supply blood to its normal vascular territory. Explanation: The moniker, “aortic root sign,” was first coined by Page et al1 on conventional angiography to describe ACCA as arising from the proximal right coronary artery or right coronary sinus. The aberrant vessel courses inferiorly behind the aortic root within the groove between the left atrium and aorta,2 hence the term “aortic root sign” (Fig. 1).FIGURE 1: Fifty-six-year-old patient with atypical chest pain. A, Right anterior oblique ventriculogram from left heart catheterization demonstrates anomalous course of the left circumflex (LCX) en face below the aortic root (classic aortic root “dot” sign; thin arrow) (LV=left ventricle). B, Electrocardiogram-gated cardiac computed tomography (CT) matched in projection of the cardiac catheterization reveals the same signature appearance of the anomalous LCX (thin arrow). C, CT correlate of the conventional aortic root “dot” sign seen on an axial image from an electrocardiogram-gated CT reveals the anomalous LCX coursing inferior to the noncoronary sinus of the aortic root (medium arrow) (RA=right atrium, RV=right ventricle, LA=left atrium). D, Volume-rendered image of the aortic root demonstrates coronary origin from the right sinus of Valsalva (asterisk) with immediate takeoff of the anomalous LCX (arrowhead) from the normal right coronary artery (large arrow).Discussion: Traditionally coronary artery anomalies (CAAs) were thought to have little significance, and were often discovered as incidental findings on angiography. However, patients may present with clinically significant disease.2 In fact, CAAs are the second most common cause of sudden cardiac death in young athletes in the United States.2 ACCA was first described by Antopol and Kugel.3 The prevalence of ACCA reported in the coronary angiography literature ranges from 0.18% to 0.67%, making it the most common CAA. Some authors postulate that the oblique angulation of its origin predisposes ACCA to atherosclerosis. However, most clinicians agree that ACCA is a benign, asymptomatic anomaly. Indeed, the retroaortic course of ACCA, as described by the aortic root sign, rarely leads to ischemia or sudden cardiac death. On the contrary, CAAs that travel along an interarterial course between the aorta and pulmonary artery are more prone to ischemia during strenuous exercise.2 Despite the low risk of ischemia and sudden death with ACCA, recognition of this anomaly is still of great clinical importance because failure to identify this aberrant vessel can lead to adverse patient outcomes, especially during cardiac surgery. Therefore, it is crucial for the angiographer as well as the radiologist to be adept at recognizing ACCA and the other coronary anomalies, especially given the ease of diagnosis with noninvasive coronary imaging techniques, such as multidetector computed tomography4 and cardiac magnetic resonance imaging.5

Use of the stereoscopic virtual reality display system for the detection and characterization of intracranial aneurysms: A Icomparison with conventional computed tomography workstation and 3D rotational angiography

ObjectiveThis study aimed to compare the diagnostic performance of the stereoscopic virtual reality display system with the conventional computed tomography (CT) workstation and three-dimensional rotational angiography (3DRA) for intracranial aneurysm detection and characterization, with a focus on small aneurysms and those near the bone. Patients and methodsFirst, 42 patients with suspected intracranial aneurysms underwent both 256-row CT angiography (CTA) and 3DRA. Volume rendering (VR) images were captured using the conventional CT workstation. Next, VR images were transferred to the stereoscopic virtual reality display system. Two radiologists independently assessed the results that were obtained using the conventional CT workstation and stereoscopic virtual reality display system. The 3DRA results were considered as the ultimate reference standard. ResultsBased on 3DRA images, 38 aneurysms were confirmed in 42 patients. Two cases were misdiagnosed and 1 was missed when the traditional CT workstation was used. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional CT workstation were 94.7%, 85.7%, 97.3%, 75%, and99.3%, respectively, on a per-aneurysm basis. The stereoscopic virtual reality display system missed a case. The sensitivity, specificity, PPV, NPV, and accuracy of the stereoscopic virtual reality display system were 100%, 85.7%, 97.4%, 100%, and 97.8%, respectively. No difference was observed in the accuracy of the traditional CT workstation, stereoscopic virtual reality display system, and 3DRA in detecting aneurysms. ConclusionThe stereoscopic virtual reality display system has some advantages in detecting small aneurysms and those near the bone. The virtual reality stereoscopic vision obtained through the system was found as a useful tool in intracranial aneurysm diagnosis and pre-operative 3D imaging.

Volume-Rendered Projection-Resolved OCT Angiography: 3D Lesion Complexity Is Associated With Therapy Response in Wet Age-Related Macular Degeneration.

PurposeTo explore whether quantitative three-dimensional (3D) analysis of choroidal neovascularization (CNV) using projection-resolved optical coherence tomography angiography (PR-OCTA) is associated with treatment response in neovascular age-related macular degeneration (nAMD).MethodsRetrospective, cross-sectional study of 51 eyes of 49 patients undergoing individualized anti-VEGF therapy for nAMD. Patients were classified as “good” or “poor” responders, requiring injections at less or more frequently than 6-week intervals, respectively. Cross-sectional PR-OCTA images were used to measure the distance between Bruch's membrane and highest CNV flow signal. The number of flow layers within the CNV and the distance between these flow layers (CNV flow thickness) were also analyzed. Two masked, independent graders measured the PR-OCTA parameters. We used 3D volume-rendered PR-OCTA to confirm the number of CNV flow layers and further evaluate CNV complexity.ResultsPoor responders had significantly greater distance between Bruch's membrane and highest CNV flow signal (P < 0.01), greater number of CNV flow layers (P = 0.022), and greater CNV flow thickness (P < 0.01). Volume-rendered PR-OCTA images confirmed the number of CNV flow layers.ConclusionsCross-sectional and 3D volume-rendered PR-OCTA provides a novel approach for quantifying CNV complexity. Our results suggest that CNV acquiring more complex 3D vascular structure are associated with more frequent long-term anti-VEGF therapy, reflecting a particular pattern of normalization or complex CNV remodeling process that characterizes these less responsive eyes.

A Generative Model for Volume Rendering.

We present a technique to synthesize and analyze volume-rendered images using generative models. We use the Generative Adversarial Network (GAN) framework to compute a model from a large collection of volume renderings, conditioned on (1) viewpoint and (2) transfer functions for opacity and color. Our approach facilitates tasks for volume analysis that are challenging to achieve using existing rendering techniques such as ray casting or texture-based methods. We show how to guide the user in transfer function editing by quantifying expected change in the output image. Additionally, the generative model transforms transfer functions into a view-invariant latent space specifically designed to synthesize volume-rendered images. We use this space directly for rendering, enabling the user to explore the space of volume-rendered images. As our model is independent of the choice of volume rendering process, we show how to analyze volume-rendered images produced by direct and global illumination lighting, for a variety of volume datasets.

Impact of Intraoperative 3-Dimensional Volume-Rendering Rotational Angiography on Clip Repositioning Rates in Aneurysmal Surgery.

Three-dimensional (3D) rotational angiography (RA), a gold standard imaging tool for the evaluation of cerebral aneurysms after clipping, can currently be performed intraoperatively in a hybrid operating room (OR). However, its role in intraoperative aneurysmal surgery is unclear. We aimed to study the value of intraoperative 2-dimensional digital subtraction angiography (2D-DSA) and 3D-RA for the evaluation of aneurysms after clipping, in terms of clip repositioning. We included patients with cerebral aneurysms who were treated with microsurgical clipping in a hybrid OR. After aneurysmal clipping and indocyanine green video angiography assessment, intraoperative 2D-DSA and 3D-RA with volume-rendering (VR) images of the clipped aneurysm were obtained. The incidence rate of clip repositioning was determined, and aneurysm-related factors associated with suboptimal clipping that required clip revision after intraoperative angiography evaluation were analyzed. Between September 2016 and August 2017, 24 consecutive patients with 35 aneurysms were treated with microsurgical clipping. A clip repositioning rate of 17.1% was revealed after intraoperative 3D-VR imaging and initial indocyanine green-video angiography. 3D-VR was able to demonstrate all aneurysmal remnants, whereas 2D-DSA helped confirm flow stagnation in compromised vessels. Challenging aneurysms of size >7 mm (P= 0.043) and neck width >4 mm (P= 0.012) were significantly associated with a higher incidence of suboptimal aneurysmal clipping. A hybrid OR, with angiography facilities for high-resolution 2D-DSA and 3D-VR images, allows neurosurgeons to perform high-quality surgery. The routine use of intraoperative 3D-RA may not be necessary; however, it is invaluable for treating challenging aneurysms.

Vascular assessment after clipping surgery using four-dimensional CT angiography.

Recent advances in computed tomography angiography (CTA) enable repeated imaging follow up for post-clipping surgery. The purpose of this study was to clarify the critical volume and configuration of the aneurysmal clip in the postoperative evaluation using volume rendering (VR) imaging, and present four-dimensional (4D)-CTA for these larger metal artifacts. A total of 44 patients with cerebral aneurysm, treated using clipping surgery, were included in this study. The metal artifact volume was assessed using CTA and the association between the type of clips and its metal artifact volume was analyzed. A VR image and a 4D-CTA were then produced, and the diagnostic accuracy of arteries around the clip or residual aneurysm on these images was evaluated. In the receiver operating characteristic (ROC) curve analysis, the cutoff value for metal artifacts was 2.32mm3 as determined through a VR image. Patients were divided into two groups. Group 1 included patients with a simple and small clip, and group 2 included patients with multiple, large or fenestrated clips. The metal artifact volume was significantly larger in group 2, and the group incorporated the cutoff value. Post-clipping status on the VR image was significantly superior in group 1 compared with group 2. In group 2, the imaging quality of post-clipping status on 4D-CTA was superior in 92.9% of patients. The metal artifact volume was dependent on the number, size, or configuration of the clip used. In group 2, evaluation using a 4D-CTA eliminated the effect of the metal artifacts.

Posterior Inferior Cerebellar Artery Aneurysm: Have You Ever Been Misdiagnosed?

The posterior inferior cerebellar artery aneurysm (PICAA), especially distal PICAA, is easily missed by a doctor, leading to misdiagnosis and treatment delays. The objective of this article is to report the computed tomography angiography (CTA) presentations of 30 cases of PICAA proved by digital subtraction angiography (DSA) or surgical operation, and analyze the causes of misdiagnosis of PICAA by CTA. Thirty cases of patients with PICAA that were proved by DSA or surgical operation were included in this study, all of whom underwent CTA before surgical procedure. The relationship between the locations of PICAA and the rates of missed diagnosis by CTA was analyzed. The detection rates of the PICAA by volume rendering (VR) images and original thin axial images of CTA were compared. Twelve cases (12 of 30, 40%) of aneurysm lied on the proximal end of posterior inferior cerebellar artery (PICA) (border with vertebral artery) and all of them (12 of 12,100%) were clearly displayed on the VR images of CTA and correctly diagnosed by doctors. Eighteen cases (18 of 30, 60%) of aneurysm lied on the distal part of the PICA, whereas only 2 of them (2/18, 11.1%) were displayed on the VR images and correctly diagnosed before surgical procedure. After surgical operation, the respective review of the CTA images demonstrated that all aneurysms (30 of 30, 100%) can be found on the thin axial images after careful observation and are shown on VR images after adjusting the display threshold when the locations of the PICAA through thin axial images were known, including the distal PICAA. Thin axial CT images are most important and reliable for the detection of distal PICAA. Overdependence on three-dimensional VR images of CTA is the main cause of misdiagnosis.

Essential Modifiers of Double Outlet Right Ventricle: Revisit With Endocardial Surface Images and 3-Dimensional Print Models.

Hearts with double outlet right ventricle are a heterogeneous group of malformations in which a comprehensive diagnostic approach is required for tailored surgical management. This pictorial essay revisits essential modifiers of clinical and surgical importance in management of the patients with double outlet right ventricle using 3-dimensional volume-rendered endocardial surface images and 3-dimensional print models. Special emphasis is paid to the infundibular morphology, including the size and orientation of the outlet septum, relative to the margin of the ventricular septal defect, and the extent of the muscular infundibulum as an additional modifier of the distance between the ventricular septal defect margin and the arterial valve or valves.

4:03 PM Abstract No. 30 Augmented virtual reality assisted treatment planning for splenic artery aneurysms: a pilot study

To evaluate the utility of augmented virtual reality (VR) in preprocedural planning for endovascular repair of splenic artery aneurysms (SAA) as compared to standard volume-rendering (SR) software. Preprocedural computed tomographic angiography (CTA) images of 14 patients with 17 SAA who had undergone endovascular repair were reconstructed using True 3D (EchoPixel, Inc., CA), a VR visualization software system. AquariusNet (TeraRecon, CA) was used for standard volume-rendering image interpretation. Three radiologists independently evaluated the number of inflow and outflow arteries using both VR and SR. Procedural angiographic images served as the gold standard. Improvement in operator confidence of VR over SR was measured on a four-point scale (1 no change, 4 significant). Clinical utility was objectively measured by VR’s ability to accurately identify all inflow and outflow arteries associated with the SAA and subjectively by operator confidence. There were 17 inflow and 22 outflow arteries associated with the SAA. The overall sensitivity, accuracy and positive predictive value for VR was similar to that of SR (91.3%, 89.7%, 84% and 88.9%, 88.9%, 84.6%, p = 0.14, respectively). However, the ability to view and manipulate images in true three-dimensions using VR markedly improved operator confidence with 93% receiving a score of at least 3 (71% = 3, 21% = 4). SAA have complex anatomy necessitating meticulous preprocedure planning. VR allows holographic visualization of images as if they were real physical objects, providing information critical for endovascular repair of SAA and thus significantly increasing operator confidence.

Compressive Giant Left Atrium

The Supplemental Figure and Video can be viewed in the online version of this article [https://doi.org/10.1016/j.athoracsur.2018.01.042] on http://www.annalsthoracicsurgery.org. The Supplemental Figure and Video can be viewed in the online version of this article [https://doi.org/10.1016/j.athoracsur.2018.01.042] on http://www.annalsthoracicsurgery.org. A 75-year-old man was admitted to our hospital with symptoms of progressive heart failure. His history revealed mitral valve replacement and tricuspid annuloplasty for severe rheumatic mitral stenosis with severe tricuspid regurgitation 13 years earlier, hypertension, and persistent atrial fibrillation. The physical examination was notable for crackles in both lungs, elevated jugular venous pressure, hepatomegaly, and severe lower-extremity edema. Electrocardiography revealed atrial fibrillation rhythm (Supplemental Fig 1A). A chest roentgenogram showed massive cardiomegaly, with a cardiothoracic ratio of 0.88 (Supplemental Fig 1B). Transthoracic echocardiography demonstrated hugely dilated left atrium (LA) (Supplemental Fig 1C, 1D; Video), a functioning prosthetic mitral valve, and reduced left ventricular systolic function with an ejection fraction of 0.15. A chest computed tomography scan revealed a giant LA measuring 19.3 × 14 cm, with compression of the right atrium, right ventricle, left ventricle, and adjacent structures (Fig 1A, 1B). The LA volume was 2,900 mL. Volume-rendered imaging demonstrated a giant LA occupying the entire mediastinum (Fig 1C). His symptoms began improving under conservative management. A reevaluation of his previous echocardiograms revealed the existence of LA enlargement (90 × 100 mm, measured from the apical 4-chamber view) and a moderate impairment of left ventricular systolic function before the index operation, and the LA failed to regress after the operation. Postoperative progression of LA enlargement was attributed to coexisting atrial fibrillation and left ventricular systolic dysfunction, because both conditions act to hinder LA regression and promote further remodeling [1El Maghraby A. Hajar R. Giant left atrium: a review.Heart Views. 2012; 13: 46-52Crossref PubMed Google Scholar]. The giant LA presented here demonstrates the extent to which the LA can expand. eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiIyYzQ0MzdmYmE1NDZhMjg3YTM3MWExOTFjYzI3YTJmYiIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjc4MzcyNjgwfQ.IP8P92FjiO0suUW7dQJxzPBoYVF9a3EKoGNghpZ4voHRC-SczQioGIuYL6kfF4QG2ddggkFiFqCjEBl4LP2Y6S0JO5r2frvgvfIv-AICmkCAJOIuUi8fn8OYeg6Tt5hcNd5x8dXTT_12RtW4CUDjs9YRm4M1W1OgT34Sx5jLKR2Py6OnSq4s6s-zIXZZ4gFa1PT4wZu5k7xnu9hszvVUrWp0g87aoW1aMZ6ZNzV0KJFGPo16XjMShyvx1nRCj-Kq6Tbcg_gTjyeoe1eVi58ZVGZg3S1QIbTNhIwIGkCTebdBD7VFq_2trk5PqBXHJ02WGoBTB1f3ERfeNSx7atszUQ Download .mp4 (5.33 MB) Help with .mp4 files Video

Investigating Decrease in Radiation Dose using Acute Chest Pain Coronary CT with 128 slice MDCT Scanner

목적 : Acute Chest Pain CCTA 검사 시 Helical scan mode (ECG-gated없이 호흡 조절만으로 움직임 없는 영상을 얻을 수 있는 carina 상부)와 후향적 ECG-gated helical scan mode로 나누어 검사 하여 두 방법의 선량과 영상의 질을 평가 하고자 한다. 대상 및 방법 : 2016년 6월부터 2017년 1월까지 Acute Chest Pain으로 응급실에 내원하여 CCTA검사를 후향적 ECG-gated helical scan mode로 검사한 환자 60명 (이하-대조군)과 Helical scan mode와 후향적 ECG-gated helical scan mode로 조합하여 검사한 환자 (이하-실험군) 60명을 대상으로 했다. 대조군은 흉부 전체 범위를 설정하고, 실험군은 좌, 우 늑골 횡격막 각 (CPA)부터 기관 분기부 (Carina)까지 후향적 ECG-gated helical scan mode로 검사 후 기관 분기부 (Carina)부터 흉부 폐첨부 (Lung apex)까지 Helical scan mode로 검사 하였다. 결과 정량적 평가 : 대조군 DLP[mGy*cm]평균값은 1670.6 mGy이며, 실험군 DLP[mGy*cm]평균값은 1035.4 mGy (Helical scan-61.8, ECGGating Helical Scan-973.5)로 환자선량의 평균값이 38.06% 감소하였다. p <0.05이여서 두 검사법의 선량은 통계적으로 유의 하였다. 대조군 및 실험군 감약계수 (HU)의 평균값 (Mean Value)은 Aortic arch가 각각 239와 444, RCA- 412와 428, LAD-319와 348, LCx-302와 343으로 측정 되었다. 정성적 평가 : 심혈관 판독전문의 2명과 CT-3D영상 재구성을 전문으로 하는 방사선사 2명이 Aortic arch, RCA, LAD, LCx의 혈관 내 조영 증강 정도와 Volume Rendering Image 재현성 및 Coronal, Sagittal MPR영상을 대조군 영상과 실험군 영상을 비교, 평가 했다. 5Grade scoring system 이용하여 각자 주관적인 평가 후 개인별 점수를 합산하여 평균 점수로 산출 한 결과 전체 평균이 4.68로 높게 평가 되었다. 결론 : 정량적 분석 결과 환자의 총선량 DLP[mGy*cm]평균값이 기존의 검사 방법에 비해 피폭선량을 줄이면서도 영상의 질을 유지 할 수 있었다. 정성적 분석 결과 측정 항목 평균값이 5점기준 4.68로 높게 평가 되었다. 그러므로 본 연구 방법을 검사에 응용하거나 적용하면 임상에 유용하고 환자의 방사선 피폭선량을 줄일 수 있을 것으로 사료된다.Purpose: In this study, an area of examination is divided into helical scan mode and retrospective ECG gated helical scan mode in order to decrease radiation dose. The practicality of this new approach is further evaluated by investigating radiation dose and its image quality. Methods: A total of 120 outpatients who visited the hospital for Acute Chest pain from June 2016 to January 2017 were examined using a cross-sectional design. 60 patients in the control group were scanned with retrospective ECG gated helical mode, and other 60 patients in the experimental group were scanned with both helical mode and retrospective ECG gated helical mode. While an area of the examination was selected from lung apex to CPA for the control group, an area of examination for the experimental group was divided into two sections: from CPA to carina trachea using retrospective ECG-gated helical scan mode, and from carina trachea to lung apex using helical scan mode. Result 1. Quantitative Analysis: On average, the control group was exposed to 1670.6 mGy of radiation, and the experimental group was exposed to 1035.4 mGy of radiation. Which means the experimental group was less exposed to radiation by 38.06% compared to the control group, and the data were statistically significant (p <0.05). 2. Qualitative Analysis: When an area of examination is divided into helical scan mode and retrospective ECG gated helical scan mode, the overall quality of Acute Chest pain CT examination is increased by 4.68 within 5 grade scoring system. Conclusions: According to the qualitative analysis, the average radiation dose is reduced by 38.06% using the newly suggested method in this study. By dividing the sections of an examined area, the overall image quality and DLP are enhanced at the same time. Therefore, if this method becomes applicable with other examinations as well, it will minimize the patients unnecessary radiation exposure and further decrease some potential risks of the examination.

Feasibility of using an inversion-recovery ultrashort echo time (UTE) sequence for quantification of glenoid bone loss.

To utilize the 3D inversion recovery prepared ultrashort echo time with cones readout (IR-UTE-Cones) MRI technique for direct imaging of lamellar bone with comparison to the gold standard of computed tomography (CT). CT and MRI was performed on 11 shoulder specimens and three patients. Five specimens had imaging performed before and after glenoid fracture (osteotomy). 2D and 3D volume-rendered CT images were reconstructed and conventional T1-weighted and 3D IR-UTE-Cones MRI techniques were performed. Glenoid widths and defects were independently measured by two readers using the circle method. Measurements were compared with those made from 3D CT datasets. Paired-sample Student's t tests and intraclass correlation coefficients were performed. In addition, 2D CT and 3D IR-UTE-Cones MRI datasets were linearly registered, digitally overlaid, and compared in consensus by these two readers. Compared with the reference standard (3D CT), glenoid bone diameter measurements made on 2D CT and 3D IR-UTE-Cones were not significantly different for either reader, whereas T1-weighted images underestimated the diameter (mean difference of 0.18cm, p=0.003 and 0.16cm, p=0.022 for readers 1 and 2, respectively). However, mean margin of error for measuring glenoid bone loss was small for all modalities (range, 1.46-3.92%). All measured ICCs were near perfect. Digitally registered 2D CT and 3D IR-UTE-Cones MRI datasets yielded essentially perfect congruity between the two modalities. The 3D IR-UTE-Cones MRI technique selectively visualizes lamellar bone, produces similar contrast to 2D CT imaging, and compares favorably to measurements made using 2D and 3D CT.

Trabecular Anatomy of the Axis Vertebra: A Study of Shaded Volume-Rendered Computed Tomography Images.

To date, trabecular morphology studies have been conducted on thin-section computed tomography (CT) scans of cadaveric bone. Here we describe the trabecular anatomy of the axis vertebra as revealed by an innovative imaging tool. Ten patients who underwent thin-slice CT scans for suspected cervical spine injury were prospectively subjected to shaded volume-rendered 3-dimensional reconstruction of the images. The trabecular anatomy thus depicted was recreated, and the mechanical vectors were deduced independently by a senior radiologist and spine surgeon and then matched. The clinical implications were postulated. The most striking trabeculae are the vertical compression trabeculae connecting the C1 facet to the C3 body. The center of the body of C2 has a space with sparse trabeculae; similarly, the pars interarticularis also has a clear void. The dens contain predominantly tensile trabeculae that are retained even in older patients. Midline remnants of the odontoid body synchondrosis persist even into late adulthood. Shaded volume-rendered imaging appears to be an excellent tool for studying the trabecular anatomy of cancellous bone. The weight-bearing trabeculae run from the C1-2 facet to the C3 body; the inferior facet contributes little to weight-bearing.

Development of a Three-dimensional Surgical Navigation System with Magnetic Resonance Angiography and a Three-dimensional Printer for Robot-assisted Radical Prostatectomy.

We sought to develop a surgical navigation system using magnetic resonance angiography (MRA) and a three-dimensional (3D) printer for robot-assisted radical prostatectomy (RARP). Six patients with pathologically proven localized prostate cancer were prospectively enrolled in this study. Prostate magnetic resonance imaging (MRI), consisting of T2-weighted sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) and true fast imaging with steady-state precession (true FISP), reconstructed by volume rendering, was followed by dynamic contrast-enhanced MRA performed with a volumetric interpolated breath-hold examination (VIBE) during intravenous bolus injection of gadobutrol. Images of arterial and venous phases were acquired over approximately 210 seconds. Selected images were sent to a workstation for generation of 3D volume-rendered images and standard triangulated language (STL) files for 3D print construction. The neurovascular bundles (NVBs) were found in sequence on non-contrast images. Accessory pudendal arteries (APAs) were found in all cases in the arterial phase of contrast enhancement but were ill-defined on non-contrast enhanced MRA. Dynamic contrast-enhanced MRA helped to detect APAs, suggesting that this 3D system using MRI will be useful in RARP.